POP MUSIC REVIEW : Lots of Clothes, Few Sparks From Hammer : Music: The rap star’s wardrobe changes smothered the momentum he had begun to build up at the Sports Arena.

Rap superstar Hammer left a nearly sold-out San Diego Sports Arena crowd sometimes dancing, sometimes sitting, but mostly in the dark Sunday night.

The light-footed singer opened his set with the apt “Let’s Get It Started,” the title track from his first album. Backed by 19 dancers, 10 backup singers, four drummers, four deejays and some indoor fireworks, Hammer hit the deck dancing, which in turn had the crowd bumping and swaying to one of his most popular songs.

Then the song ended, and the lights went out.

In darkness and silence, most of the crowd (with the exception of those on the arena floor) took a seat. The crowd’s adrenaline pumps shut down while Hammer and his crew switched costumes.

Then Hammer got it going all over again. Dressed in a long white coat, black trousers and white fedora, a classic “mack daddy” outfit, Hammer had the crowd up and dancing again with “Turn This Mutha Out,” another hit from his first album.

Another costume change in the dark, however, upended the momentum Hammer and his crew had just revived.

Tired of the forced aerobics, most of the audience in the upper levels kept to their seats during the middle portion of the show.

During nearly every number, the full Hammer assembly took up the entire stage, overshadowing the singer to the point that he seemed like just one of the group.

Not that watching him was particularly worth the trouble.

For all his virtuosity as a dancer, Hammer rarely cut loose with the moves he showcases on his videos. Instead, he spent most of his time strutting from side to side, gyrating here and there, but mostly leaving the dancing to the talented troupe behind him.

Four songs into his 12-song set, Hammer departed from the funky dance tunes for the Chi-Lites’ 1971 ballad “Have You Seen Her.” The song--the first he played from his mega-hit second album, “Please Hammer Don’t Hurt ‘Em”--was preceded by some standard stage banter about dedicating the song to the men of San Diego. Though forced, the talk rejuvenated the crowd.

That renewal of enthusiasm actually survived a costume change and carried over into “Pray,” another hit from the second album. The raucous song had Hammer at his best as a singer-rapper, but, much to the disappointment of the crowd, the song and its energy faded during another costume change.

For the last few songs, Hammer revved up, particularly for his overplayed smash hit, “U Can’t Touch This,” for which he performed more of his trademark dance steps than for any other song.

The encore was, of course, Hammer’s newest song, “Too Legit to Quit.” With most everyone in the stands doing the requisite hand motions “signing” the words in the title, it was one of the few times during the evening that the crowd’s energy matched that of the dancers and musicians on stage.

Then Hammer and his group broke into a “Soul Train”-like dance line, which, as dance lines go, was extremely entertaining. The caliber of Hammer’s dancers is far better than anything “Soul Train” could muster. But, oddly enough, Hammer, who remained on the outskirts, didn’t join in the fun.

The opening acts, Jodeci and Boyz II Men, played the customary abbreviated sets, but both had the pre-Hammer audience on its feet.

Jodeci spent most of its set goofing around, the members dropping their pants and writhing on the ground, but their vocal talent nevertheless came through. They easily switched back and forth between their hard New Jack style and a much softer Motown approach. Though the group didn’t pull any dance moves that Michael Jackson hadn’t done at the age of 5, it did display ample range in its voices.

Boyz II Men gave a clean set of music after politely introducing itself to a crowd that needed no introductions. The group’s first album went quadruple platinum, and a good share of the buyers were in the audience just for the Boyz.

In introducing themselves, some of the group members gave their ages--ranging from 19 to 21--which made the younger fans in the audience scream in delight. In all, the set was polished and fun, mixing equal parts solid music and nifty choreography.